Communication networks can be built in many different network topologies, such as a ring, mesh, linear, linear chain, tree, and the like. Conventionally, network protection is provided for at layers one and below, such as through SONET, SDH, and the like. Typical protection schemes can include Automatic Protection Switching (APS), Uni-directional Path Switched Rings (UPSRs), two and four fiber Bi-directional Line Switched Rings (BLSRs), and the like. However, networks are typically unprotected at layer two (e.g., Ethernet) and above. For example, Ethernet-based access and aggregation networks are typically designed in a tree structure, and thus lack network protection.
Modern networks, such as access and aggregation networks, are moving towards Ethernet as the universal medium. However, Ethernet is not quite robust enough for carrier transport applications. Ethernet standards are evolving towards carrier-grade performance, and equipment providers today provide various different solutions for Ethernet-based network protection. For example, layer zero/one protection can be provided through Ethernet-over-SONET or SDH solutions. At layer two, various solutions have been presented, such as Ethernet Protection Switching (EPS) which is not 802.1ag-based, Resilient Packet Ring (RPR), Rapid Spanning Tree Protocol (RSTP), and Spanning Tree Protocol (STP). At layer two-and-a-half, Multi-Protocol Label Switching (MPLS) fast reroute (FRR) can provide network protection. Finally, network protection can be achieved at layer three through Internet Protocol (IP)-based protection schemes, such as Open Shortest Path First (OSPF) recovery. Some of these foregoing schemes can achieve SONET/SDH-like recovery (i.e., less than 50 msec), and some cannot and require 100 msec to 30 sec to recover.
Ethernet-layer services, such as the Metro Ethernet Forum (MEF) E-LINE and E-LAN services, are rapidly growing in network deployments. Disadvantageously, current network protection approaches described herein may require the use of self-configuring networks, such as STP, which is not compatible with fixed (managed) configuration Ethernet networks, such as Provider Backbone Transport (PBT). Additionally, these schemes may require specific hardware or software for operation, such as RPR due to non-Ethernet. Further, these schemes are not IEEE 802.1ag based. IEEE 802.1ag provides Connectivity Fault Management, i.e. Ethernet Operations Administration and Maintenance (OAM). IEEE 802.1ag is a major thrust with service providers to enable carrier-grade Ethernet. Finally, some of these schemes require other protocols besides Ethernet, such as MPLS.